PMID- 9572158
OWN - NLM
STAT- MEDLINE
DCOM- 19980512
LR  - 20191102
IS  - 1528-7394 (Print)
IS  - 0098-4108 (Linking)
VI  - 53
IP  - 8
DP  - 1998 Apr 24
TI  - Effects of silica exposure on substance P immunoreactivity and preprotachykinin 
      mRNA expression in trigeminal sensory neurons in Fischer 344 rats.
PG  - 593-605
AB  - Trigeminal sensory neurons innervate the nasal cavity and may release substance P 
      (SP) upon exposure to inhaled irritants. The purpose of this study was to 
      determine if silica dust, an occupational irritant causing inflammation, 
      activates sensory neurons supplying the nasal cavity. Male Fischer 344 rats were 
      placed in inhalation chambers and exposed daily to 2 mg/m3 of fresh silica 
      (average diameter 1 microm) for 6 mo. Following exposure, the trigeminal ganglia 
      (TG) were removed and prepared for SP immunocytochemistry and for 
      preprotachykinin (PPT) autoradiographic in situ hybridization. The SP-like 
      immunofluorescence in TG neurons was subjectively categorized as high, moderate, 
      or low (background) intensity. In situ hybridization autoradiographs were 
      quantified on the basis of grain density using digital imaging analysis. The SP 
      immunoreactivity and PPT mRNA expression in the TG neurons were significantly 
      increased after silica inhalation. The proportion of highly positive 
      SP-immunoreactive neurons shifted from 1.30 +/- 0.58% in controls to 11.30 +/- 
      1.15% after silica treatment. The neurons exhibiting high grain density for PPT 
      mRNA increased from 1.50 +/- 0.87% in controls to 11.67 +/- 0.58% in the silica 
      group. Thus, inhalation of silica causes upper airway irritation resulting in 
      increased levels of immunoreactive neuronal SP and PPT mRNA. These findings 
      suggest that silica activates sensory pathways that may be involved in nasal 
      inflammation.
FAU - Hunter, D D
AU  - Hunter DD
AD  - Department of Anatomy, West Virginia University, Morgantown, USA.
FAU - Castranova, V
AU  - Castranova V
FAU - Stanley, C
AU  - Stanley C
FAU - Dey, R D
AU  - Dey RD
LA  - eng
GR  - HL 35812/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - England
TA  - J Toxicol Environ Health A
JT  - Journal of toxicology and environmental health. Part A
JID - 100960995
RN  - 0 (Air Pollutants)
RN  - 0 (Dust)
RN  - 0 (Protein Precursors)
RN  - 0 (RNA, Messenger)
RN  - 0 (Tachykinins)
RN  - 0 (preprotachykinin)
RN  - 33507-63-0 (Substance P)
RN  - 7631-86-9 (Silicon Dioxide)
SB  - IM
MH  - Air Pollutants/adverse effects/immunology
MH  - Animals
MH  - Dust
MH  - Immunohistochemistry
MH  - In Situ Hybridization
MH  - Inflammation/*chemically induced/immunology
MH  - Inhalation Exposure
MH  - Male
MH  - Protein Precursors/*drug effects/immunology
MH  - RNA, Messenger/biosynthesis/drug effects
MH  - Rats
MH  - Rats, Inbred F344
MH  - Silicon Dioxide/*adverse effects/pharmacology
MH  - Substance P/drug effects/*immunology
MH  - Tachykinins/*drug effects/immunology
MH  - Trigeminal Nerve/*drug effects/immunology
EDAT- 1998/05/08 00:00
MHDA- 1998/05/08 00:01
CRDT- 1998/05/08 00:00
PHST- 1998/05/08 00:00 [pubmed]
PHST- 1998/05/08 00:01 [medline]
PHST- 1998/05/08 00:00 [entrez]
AID - 10.1080/009841098159051 [doi]
PST - ppublish
SO  - J Toxicol Environ Health A. 1998 Apr 24;53(8):593-605. doi: 
      10.1080/009841098159051.